Generalized tracks, area cladograms and tectonics in the Caribbean

TLDR: In this article, the authors used parsimony analysis of endemicity with progressive character elimination (PAE-PCE) to identify generalized tracks and nodes, and parsimony analyses of paralogy-free subtrees to infer their historical relationships.

Abstract: Aim To test the ‘naturalness’, or integrity as a biogeographical unit, of the Caribbean subregion. Location A wide geographical range in the Caribbean (32° N, 115° W; 10° S, 56° W). As units of analysis, 43 biogeographical provinces were used: 24 assigned to the Caribbean subregion, and 19 provinces situated north and south of this subregion, which were used as outgroup areas. Methods We analysed 895 plant and animal taxa distributed in the Caribbean. We used parsimony analysis of endemicity with progressive character elimination (PAE-PCE) to identify generalized tracks and nodes, and parsimony analysis of paralogy-free subtrees to infer their historical relationships. Results We obtained 10 generalized tracks and five nodes from the panbiogeographical analysis and 14 most parsimonious general area cladograms from the cladistic biogeographical analysis. In general terms, the results of both analyses are congruent, reflecting a similar history of vicariant events in the Caribbean area. Main conclusions Panbiogeographical and cladistic biogeographical analyses reflected a similar history of vicariant events in the Caribbean: the Caribbean subregion as it is currently defined does not represent a ‘natural’ biogeographical unit; the Isthmus of Tehuantepec might not represent a conspicuous biogeographical barrier; and the biogeographical relevance of the Isthmus of Panama exceeds the last 3 million years, which is the time it has operated as a connection between North and South America.